Advancements of submicron technologies in semiconductor manufacturing make it possible to form large-scale logic in a single IC chip. However, little progress has been made in a technique for reducing intervals between I/O (Input/Output) pads on the chip. This means that the size of the chip is determined by the number of I/O's rather than the number of logics. Even if a logic region occupies an extremely small portion of the entire chip, the die size cannot be reduced because of the need to maintain a predetermined number of I/O's, leading to an IC chip having a relatively small ratio of circuit area to total chip area.
On the other hand, the design concept of sharing a bus by various I/O's and devices has reached the limit in speeding up the system, and an attempt is being made to solve a problem regarding the bandwidth of the bus by adopting, for example, a crossbar switch system. However, the technique like the crossbar switch system results in forming too many pins, also leading to an IC chip having an extremely small ratio of logic area to total area.
Japanese Patent Publication No. 8-77317 discloses an IC chip with wireless communications capability incorporated in an IC card. The IC chip with the wireless communications capability incorporated in the IC card makes communications not with an IC chip that can be connected via wire, but with an access control system or a charging system, which inherently has a difficulty in establishing a wired connection. In other words, the technical idea of the wireless communications disclosed and suggested in Japanese Patent Publication No. 8-77317 merely chooses wireless communications as a communication function for an IC chip carried with an individual or mounted to a vehicle, and is, therefore, more or less the same as the technical idea of mobile communications with cellular phones or cordless phones.
Additionally, it has been known that an antenna is formed on the surface of the IC chip with wireless communications capability. Such an IC chip with wireless communications capability is also intended for incorporation into a card or a token (a round piece of metal used instead of coins in arcade games or the like), and wireless communications are disclosed or suggested, at best, as means for inputting and outputting data to and from the card or the token used as a mobile unit.